Siemens SINUMERIK 840D sl Function Manual page 151

Figure 7-16
CDC tolerance
As tolerance in the crosswise data comparison for the extended n
$MA_SAFE_POS_TOL is not used, but instead
for 840D sl:
MD36947 $MA_SAFE_VELO_X_HYSTERESIS
for SINAMICS S120:
p9547 SI Motion SSM (SGA n<n
This MD defines the maximum permissible velocity tolerance between the two monitoring
channels, and during ramp-up, a plausibility check is made to the speed limit set in
$MA_SAFE_VELO_X. In this case, the following must apply:
$MA_SAFE_VELO_X_HYSTERESIS ≤ 3/4 $MA_SAFE_VELO_X,
otherwise, Alarm 27033 "Axis %1 parameterization of MD
$MA_SAFE_VELO_X_HYSTERESIS invalid, error code %4" is issued. A crosswise data
comparison error is only detected when the velocity deviation between the two monitoring
channels is greater than the tolerance in $MA_SAFE_VELO_X_HYSTERESIS; Alarm 27001
or 27106 is then output and the corresponding stop response is started.
Safety Integrated
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
n<nx value range with synchronization and hysteresis
) velocity hysteresis (CU)
x
Safety functions integrated in the system/drive
7.6 Safe speed range detection "n<nx"
functionality, machine data
x
151